Greetings,

I got the below WARNING in net-next/master (head commit f498354793d5)
and the first bad commit is

commit c54419321455631079c7d6e60bc732dd0c5914c5
Author: Pravin B Shelar <pshelar@nicira.com>
Date:   Mon Mar 25 14:49:35 2013 +0000

    GRE: Refactor GRE tunneling code.
    
    Following patch refactors GRE code into ip tunneling code and GRE
    specific code. Common tunneling code is moved to ip_tunnel module.
    ip_tunnel module is written as generic library which can be used
    by different tunneling implementations.
    
    ip_tunnel module contains following components:
     - packet xmit and rcv generic code. xmit flow looks like
       (gre_xmit/ipip_xmit)->ip_tunnel_xmit->ip_local_out.
     - hash table of all devices.
     - lookup for tunnel devices.
     - control plane operations like device create, destroy, ioctl, netlink
       operations code.
     - registration for tunneling modules, like gre, ipip etc.
     - define single pcpu_tstats dev->tstats.
     - struct tnl_ptk_info added to pass parsed tunnel packet parameters.
    
    ipip.h header is renamed to ip_tunnel.h
    
    Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

[   27.507156] libceph: loaded (mon/osd proto 15/24)
[   27.515409] ------------[ cut here ]------------
[   27.518917] WARNING: at /c/kernel-tests/src/stable/net/batman-adv/hard-interface.c:92 batadv_is_on_batman_iface+0x5c/0x7a()
[   27.521935] Hardware name: Bochs
[   27.525356] Cannot find parent device
[   27.528296] Modules linked in:
[   27.529923] Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc4-00896-g03ba910 #794
[   27.531747] Call Trace:
[   27.534683]  [<ffffffff81098ab4>] warn_slowpath_common+0x83/0x9e
[   27.536338]  [<ffffffff81098b72>] warn_slowpath_fmt+0x46/0x48
[   27.537872]  [<ffffffff828e6402>] ? rcu_read_unlock+0x1c/0x2d
[   27.539441]  [<ffffffff810ca498>] ? local_clock+0x19/0x52
[   27.541023]  [<ffffffff82c0e796>] batadv_is_on_batman_iface+0x5c/0x7a
[   27.542803]  [<ffffffff82c0efe2>] batadv_hard_if_event+0x8f/0x285
[   27.544551]  [<ffffffff828e4ff0>] register_netdevice_notifier+0x71/0x17e
[   27.550617]  [<ffffffff8420a030>] ? batadv_iv_init+0x3f/0x3f
[   27.552248]  [<ffffffff8420a114>] batadv_init+0xe4/0x104
[   27.553770]  [<ffffffff810020be>] do_one_initcall+0x7f/0x13d
[   27.555386]  [<ffffffff84177eb0>] kernel_init_freeable+0x141/0x1d0
[   27.557177]  [<ffffffff84177734>] ? do_early_param+0x8c/0x8c
[   27.558813]  [<ffffffff82c1f146>] ? rest_init+0xda/0xda
[   27.560348]  [<ffffffff82c1f154>] kernel_init+0xe/0xdb
[   27.561813]  [<ffffffff82c694ac>] ret_from_fork+0x7c/0xb0
[   27.563356]  [<ffffffff82c1f146>] ? rest_init+0xda/0xda
[   27.564974] ---[ end trace f78f9f0651ffcb0b ]---

git bisect start 03ba9107c92bdc2eec1d14ea19d5a00209969d87 v3.8 --
git bisect good cb715a836642e0ec69350670d1c2f800f3e2d2e4  #    10  2013-03-29 14:42:04  Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect good b67bfe0d42cac56c512dd5da4b1b347a23f4b70a  #    10  2013-03-29 17:23:34  hlist: drop the node parameter from iterators
git bisect good 59d8e5eb2bd5593d8220db0e25206cdfc42e83ea  #    10  2013-03-29 20:04:53  Merge branch 'akpm' (fixes from Andrew)
git bisect good 71420228feb826b365b3fef4de01e83c00e9151d  #    10  2013-03-29 22:46:41  Merge remote-tracking branch 'origin/drm-intel-fixes' into drm-intel-nightly
git bisect good 5470b462c3f0c6fa980c320968a165bd0f34ca8d  #    10  2013-03-30 00:08:49  Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
git bisect  bad 38502af77e07b5d6650b9ff99a0b482d86366592  #     0  2013-03-30 00:16:41  tuntap: set transport header before passing it to kernel
git bisect good 0465277f6b3fd0535428ae935644ac30ce903de0  #    10  2013-03-30 01:46:40  ipv4: provide addr and netconf dump consistency info
git bisect good 21168245031062212c0b805d0bd466ee6dd4a16f  #    10  2013-03-30 04:28:14  dsa: factor freeing of dsa_platform_data
git bisect  bad cb6bf35502d53364d15737295bc64f804c4587ce  #     0  2013-03-30 05:47:34  firewire net, ipv6: IPv6 over Firewire (RFC3146) support.
git bisect  bad 206aaafcd279e2cb836d772282517540c6cb3814  #     0  2013-03-30 05:55:36  VXLAN: Use IP Tunnels tunnel ENC encap API
git bisect good 25c7704d8bdcf6746dab4397953df51759924b37  #    10  2013-03-30 07:21:49  ipv4: Fix ip-header identification for gso packets.
git bisect  bad c54419321455631079c7d6e60bc732dd0c5914c5  #     0  2013-03-30 08:42:46  GRE: Refactor GRE tunneling code.
git bisect good eaac5f3d3ad33547b299935e6db0cfc7be9a576a  #    10  2013-03-30 10:11:30  net: Print functions in /proc/net/ptype without the offset.
git bisect good eaac5f3d3ad33547b299935e6db0cfc7be9a576a  #    30  2013-03-30 14:14:09  net: Print functions in /proc/net/ptype without the offset.
git bisect  bad 03ba9107c92bdc2eec1d14ea19d5a00209969d87  #     0  2013-03-30 15:34:09  Merge remote-tracking branch 'net-next/master' into devel-inn-x86_64-2013-03-27-06-54

Thanks,
Fengguang